Probe Information - Conductivity

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Data Probe Information Page: Conductivity ProbeAlexa R, Sarah E, Chris M, Jay F

Purpose of Probe

  • Probe quickly determines the total concentration of ions in the sample.
  • Accurate on-site measure of total dissolved solids (TDS).

How do Scientists Use this Measurement?



Resources

Add links to relevant online resources, e.g calibration curves, vendor pages, etc.



Diagram or Photo of Probe Setup


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Setup / Calibration Instructions

Record the steps that a student would use to calibrate or use this probe.
  • Rinse the tip of the Conductivity Probe with distilled water. Optional: Blot the inside of the the electrode cell dry ony if you are concerned about contamination.
  • Insert the tip of the probe into the sample being tested. Important: Be sure the electrode surfaces in the elongated cell are completely submerged in the liquid.
  • While gently swirling the probe, wait for the reading on your computer. Warning: Do not completely submerge the sensor.
  • Rinse the end of the probe with distilled water before taking another measurement.

Do I Need to Calibrate the Conductivity Probe?

  • Should not need to, but we did not see the expected values when we tested some standard samples:
  • When we tested distilled water, we got 12 muS/cm for all three probes.
  • When we tested the 1000 muS/cm standard solution, we got 953, 977, 1059, 1126muS/cm
  • When we measured pond water, and we got 510, 523, 581, 614.

Calibration Process

  • Step 1 - Select "calibrate" in the sensor menu; choose appropriate channel that you want to calibrate.
  • Step 2 - Select "calibrate now" button on calibration screen.
  • Step 3 - Place sensor in air; Enter "0" in "Reading 1 known value" field, and select "Keep". Note: Be sure that the probe is still in air when you hit the "Keep" button.
  • Step 4 - Place sensor in standard solution; Enter "1000" in "Reading 2 known value" field, and select "Keep". Note: Be sure that the probe is still in the standard solution when you hit the "Keep" button.
  • Step 5 - Select "OK" on "Sensor Settings."
  • All done!

How do I know that the probe is working properly?

  • Local drainage water (from in front of Chafee) reads between 400-500 muS/cm

Possible Applications/Projects